title: Imaging biological macromolecules by STM: quantitative interpretation of topographs.
abstract: Methods are discussed which permit the calibration of x-, y-, z-sensitivities, non-linearities and frequency responses of the scanning device of a scanning tunneling microscope (STM) either by interferometry or directly from STM topographs. A technique is presented to measure the frequency response of the complete STM feedback unit and to derive a maximum speed in z direction which allows one to estimate the maximum scanning speed still permitting one to track surface corrugations. The signal transfer characteristics of a STM are evaluated in a direct comparison with high resolution transmission electron microscopy on an identical specimen area. The various effects of contaminants between tip and specimen and the finite tip radius receive special attention.
authors.affiliation: M.E. Müller Institute for High Resolution Electron Microscopy, University of Basel, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Stemmer
authors.forename: A
authors.initials: A
authors.lastname: Engel
mesh_terms: D002473:Cell Wall / Q000648:ultrastructure; D006094:Gram-Positive Bacteria / Q000648:ultrastructure*; D007368:Interferometry; D008854:Microscopy, Electron; D016252:Microscopy, Scanning Tunneling; D013604:T-Phages / Q000648:ultrastructure*